Drill bit forging machine



July 14, 1953 A. w. MlTcHHARr DRILL BIT FoRGINc;v MACHINE 2 sheets-Sheet 1 Filed April 25. 1949 S\\\\\\\- \\\\nl l I@ N T @INM l R. mv

July 14, 1953 A. w. MlTcHHAR-r DRILL BIT FORGING MACHINE Filed April 25, 1949 2 Sheets-sheet 2 V//wa mymwf ATI'CIRNIYB Patented July 14, 1953 UNITED STATES PATENT OFFICE n 2,645,138 Darm. Brr FORGING 'MACHINE Albert W. Mitchhart, Time, ohio Application April z5, 1949, serial No. 89,478

This invention relates to machine tools of the air hammer type particularly as used in forging or swedging, and in particular an air compressor actuated hammer for swedging well drill bits and the like against an adjustable anvil and in which the speed and stroke of the hammer are regulated by adjusting air in the compressor through suitable valves.

The purpose of this invention is to provide a forging machine particularly adapted for swedgingV well drill bits in which greater flexibility of control is provided for regulating the speed and stroke of the hammer.

' In the usual type of trip hammer the speed may be controlled by a valve through which compressed air is supplied to the hammer and the stroke may be adjusted by setting cams or other operating levers but for accurate work such as forging or swedging drill bits to exact dimensions it is desired to provide greater ilexibility of control. With this thought in mind this invention contemplates a forging machine wherein the hammer is actuated by compressed air in a cylinder in combination with a piston forming a movable cylinder head with the piston forming the cylinder head actuated by an eccentric.

The object of this invention is, therefore, to provide means for mounting and controlling the hammer of -a forge whereby the hammer is actuated by impulses imparted to compressed air in 'a cylinder and in which the pressure and volume of the air in the cylinder are readily adjustable.

Another object of the invention is to provide a forge in which the hammer is actuated by an eccentric in combination with an air compressor wherein an anvil coacting with the hammer is adjustable so that work carried by the anvil may be moved to or from the hammer or set at substantially any angle in relation thereto.

Another object of the invention is to provide means for adjusting the speed and stroke of the hammer of a forge while the hammer is operating.

l A further object of the invention is to provide an' improved forge for drill bits and the like in which the hammer may be controlled and the drill bit adjusted which is of a comparatively simple and economical construction.

With these and other objects in view the invention embodies a hammer carried on therend of a piston rod with the piston mounted in a cylinder wherein another piston forming the head of the cylinder is actuated by an eccentric, in which air between the pistons is controlled and in which 2 av drill bit or the like is carried by a traveling and pivotally mounted carriage.

Other features and advantages ofthe invention will appear from the following description taken in connection with the drawings wherein:

Figure 1 is a longitudinal 'section through the machine with parts shown in elevation.

Figure 2 is a plan view of the machine with Y ing thereforand also showing a pinion and rack` through which the position of-the carriage is adjusted. Y

Figure 6 is a detail takenon line 6-6 of Figure 2 showing a locking pin by which the carriage is held in adjusted position.

Referring now to the drawings wherein like reference characters denote corresponding parts y the improved forging machine of this invention includes hammerA I0 actuated by air compressor cylinderll, a motor I2 for imparting impulses to air in the cylinder, a` carriagefl3 that is pivotally mounted on aA base Ill and a platform I5 on which the base and carriage are positioned.

The hammer Il) is carried on the end of a'pisr ton rod I6 of a piston I'I that is positioned in the cylinderl I I and the piston rod is slidably mounted in a bearing stand I8 land provided withy a spring I9 that forms a resilient bumper for arresting the piston should the Work be accidently removed from the path of the hammer.

The cylinder is valso provided with another piston 20 that `forms a cylinder head and this piston is actuated through a piston rod 2I that is slidably mounted yin abearing 22 and connected througha flexible coupling 23 to a crank shaft 24, the opposite end of which is carried by a bolt 25 in a slot 26 of a disk 2'I on a shaft 28. The bolt 25 is thereby eccentrically mounted on the disk 21 andthe disk is rotated by suitable transmission means from the motor or engine I 2 which iscarried by a stand 29 on a iloor or plate 30.

The motor or engine I2 actuates the piston 20 with a reciprocatingor vibrating action, the piston beingI operated through the eccentric and crank shaft24 and piston rod 2| and with the valves of the cylinder closed the air between the pistons will drive the pistons I1 with the hammer I6 forward and backward with the travel of the piston 20.

The cylinder is provided with a main control valve 3| that is manually actuated by a crank 32 and this valve is connected to an intermediate port 33 of the cylinder through a nipple 34 and a cross connection 35. The cross connection is provided with side connections 36 and 31 and these connections are provided with balancing valves 38 and 39 respectively. The valves 38 and 39 and manually actuated to adjust the length of the stroke or the distance the piston |1 travels. The connections 36 and 31 are also provided with check valves with a check valve 40 in the connection 36 and a check valve 4| in the connection 31. With the valve 3| open air pushed by the piston 26 is permitted to escape or air may be drawn in so that the piston |1 will remain stationary. With the valve 3| closed the air compressed by the inward movement of the piston pushes piston I1 to operate the hammer and when the piston 20 starts back it creates vacuum, drawing the piston I1 back. To set the pistons closer together the Valve 39 is opened which permits air to escape through the check valve 4| and when the piston |1 is adjusted to the distance or length of travel desired the valve 39 is closed and the pistons 20 1 and I1 will remain the same distance apart. When it is desired to shorten the length of stroke or travel of the piston |1 the valve 38 is opened which permits air to be drawn in through the check valve 40 as the piston 26 moves backward and when the piston |1 has traveled the desired distance the valve 38 is closed and the length of travel will continue to the adjusted stroke. By shortening the length of travel of the piston I1 the force of the hammer blow or of the die is reduced. By lengthening the distance of travel of the piston I1 the force of the blow of the hammer or die is increased. The force of the blow of the hammer or die can, therefore, be controlled to any force desired by adjusting the valves. This force of the hammer or die may also be controlled or adjusted by the valve 3| as if this valve is open slightly, allowing air to escape when the piston 20 travels toward the center and allowing the air to be drawn in as the piston travels away from'the center it will be possible to obtain substantially any force of blow desired. The force is dependent upon the opening provided through the valve 3|. With the valve 3| open the piston I1 remains stationary and with the valve closed the piston I1 travels with the piston 20 and by adjusting the opening of the valve 3| the hammer is controlled from the heaviest blow to a light tap or brought to a quick stop.

In the design shown a drill bit 42, which illustrates the work, is held in position by guides 43 and 44 and maintained in position by a clamp 45 having a crank 46, as illustrated in Figure 4. This clamp may be located at any suitable point and a clamp of any type may be used. The guides 33 and 34 are provided with openings 41 and 48 respectively and the guides are maintained in the position shown by brace bars 49. These guides are slidably mounted on the carriage I3 and the lower edges are provided with slots 50 and 5| respectively which receive guide bars 52 and 53, the ends of which are provided with stops 54 and 55. The carriage I3 is also provided with a bumper or stop 56 having a work engaging element 51 thereon as shown in Figure 1.

The carriage I3 is pivotally mounted by a pin 36 on the base I4 and may be adjusted to different positions, as illustrated in Figure 2, to adjust the point of a drill bit in relation to the hammer I6 whereby the point of the drill may be hammered to any suitable shape. The hammer may also be replaced by a die so that substantially any curvature or shape desired may be provided on the end of a drill bit or other work. The carriage is maintained in adjusted positions by a spring pin 59, illustrated in Figure 6, wherein the pin is mounted in a bracket 6I) secured to the carriage by bolts 6| and positioned whereby the pin follows an arcuate bar 62 which is provided with openings 63 that register with the pin.

' The pin is urged downwardly with the lower end in-one of the openings 63 by a spring 64, the lower ends of which bear against a washer 65 that is secured by welding or other means to the pin.

The base I4 is mounted on wheels 66 and the forward end thereof is provided with a crank 61 that is rotatably mounted in bearings 68 and 69. as shown in Figure 3. The intermediate part of the crank is provided with an offset section 10 on which a crank pin 1| with a head 12 on the lower end is carried. The pin 1| extends through a slot 13 in the plate 36 and, thereby provides means for locking the base and carriage in operative position upon the plate or supporting frame. The lower surface of the base |4 is provided with a rack 14 that meshes with a pinion v15 on a crank 'i6 that is journalled in bearings 11 and 13 of the platform l5 of which the plate 30 forms the upper surface. By this means the base and carriage may be moved toward or away from the hammer to adjust the position of the work or drill bit.

In the design shown the cylinder I is provided with lubricating means including an oil tube 30 extended from a supply chamber 8| and provided with connections 82 and 83 to the cylinder as shown in Figure 1.

With the parts arranged in this manner a drill bit or other work may be adjusted in relation to the hammer so that the sides of the bit, as well as the end thereof may be forged. Furthermore with the parts arranged in this manner the platform may be set in a horizontal position as shown and may also be set in a vertical position or adjusted to any suitable angle. The anvil or work holding elements may also be raised or lowered by blocking or other means so that the position thereof is adjustable in substantially all directions in relation to the hammer or die.

It will be understood that other modifications may be made in the design and arrangement oi' the parts without departing from the spirit of the invention.

What is claimed is:

l. A forging tool having a reciprocating hammer comprising an anvil, means pivotally mounting the anvil so that the positions of said anvil can be adjusted in relation to the hammer, a cylinder,a hammer piston in the cylinder having a. piston rod on which the hammer is carried, a head piston positioned in the cylinder and having a piston rod extended from the end of the cylinder. an eccentric to which the piston rod of the said head piston is connected, power means for actuating the eccentric, a valve communicating with the intermediate part of the cylinder for controlling the pressure and volume of air in the cylinder between the pistons, balancing valves in communication with the former valve and check valves in communication with the balancing vvalves for adjusting thestroke and force of the hammer piston, and means 'for kactuating `the rvalve for controlling the pressure and volume of a pistonv rod extended therefrom, an eccentric, a crank shaft connecting the piston rod of the head piston to the eccentric, power means for actuating the eccentric, valve means communicating with said cylinder for controlling the volume and pressure of air in the cylinder between the pistons, a work holder positioned in the pathfof the die carried by the piston rod of theY pistonr in the cylinder, a platform upon which the work holder',

cylinder and eccentric are positioned, rack and pinion means `'moving the work holdertoward or away from 'the die, means pivotally mounting the work holder whereby the work holder may be adjusted to various angular positions in relation to the die, and a spring actuated locking means for securing the work holder in adjusted positions.

3. In a forging tool, the combination which comprises a cylinder, a pistonin the cylinderhaving a piston rod on the outer end of which a die is carried, a head piston in the cylinder having a piston rod extended therefrom, an eccentric, a crank shaft connecting the piston rod of the head piston to the eccentric, power means for actuating` the eccentric, valve means communicating with said cylinder for controlling the volume and pressure of air in the cylinder between the pistons, a workholder positioned in the path of the die carried bythe piston rodof the piston in the cylinder, a platform on which the parts are carried, -rack and pinion means actuating the'work holder toward or away from the die, crank actuated locking means for securing the workholder is carried, a head piston inthe cylinder having ing a piston rod on the outer end of which a die Y is carried, a head piston in the cylinder having a piston rod extended therefrom, an eccentric, a crank shaft connecting the piston rod ofthe head piston to the eccentric, power means for actuating the eccentric, valve means communicating with said cylinder for controlling the volume and pressure of air in the cylinder between the pistons, a work holder positioned in the path of the die carried by the piston rod of the piston in the cylinder, a platform on which the parts are carried, rack and pinion means actuating the work holder toward or away from the die, crank actuated means for securing the work holder in adjusted positions on the platform, guide means slidably mounted on the platform and engaging the work for adjusting the position of the work in the work holder, means for clamping the work in adjusted positions in the said work holder, pin means pivotally mounting the platform whereby work may be swung laterally in relation to the die, and spring actuated means for securing the work holder in laterally adjusted positions.

5.V In a forging tool, the combination which comprises a cylinder, a piston in the cylinder having a piston rod on the outer end of which a die is carried, a head piston in the cylinder having a piston rod extended therefrom, aneccentric,"a crank shaft connecting the piston rod of the head piston tothe' eccentric, power means for actuating the eccentric, a manually actuated valve comjmunicating with the interior of the cylinder between the pistons for controlling the passage of air into and out'of the cylinder, 'a Work holder positioned in the path of the die carried by the piston rod of the piston in the cylinder, and rack andpinion means adjusting the positions of the said work holder.

r6. In a yforging tool, the combination which comprises a cylinder, a piston in the cylinder having -a piston rod on the outer end of which a die is carried, a head piston in the cylinder having a piston rod extended therefrom, an eccentric, a crank shaft connecting the piston rod of the head piston to the eccentric, power means for actuat-l ing the eccentric, a manually actuated valve communicating with the interior of the cylinder between the pistons for controlling the passage of air into and out of the cylinder, balancing valves in communication with the manual-ly controlled valve for adjusting the stroke and position ofthe piston on the piston rod of which the die is carried, check valves in communication with the balancing valves, a work holder positioned n the path of the die carried by the piston rod of the piston in the cylinder, and rack and pinion means adjusting the position of the said work holder.

7. In a forging tool, the combination which comprises ar cylindergal piston in the cylinder having y-a piston lroel on the outer endof which a die is carried, a head piston inthe'cylinder having a piston rod extended therefrom, an eccentric, acrank shaftconnecting the piston rod of thehead piston to the4 eccentric, powery means for actuating vthe eccentric, `a manually actuated valve communicating with the interior of the cylinderbetween the pistons for controlling the passage of air into and out of the cylinder, balancing valves in communication with the manually controlled valve for adjusting the stroke and position of the piston of the piston rod on which the die is carried, a check valve in communication with the balancing valves, a work holder positioned in the path of the die carried by the piston rod of the piston in the cylinder, a carriage on which the work holder is mounted, rack and pinion means for adjusting the carriage longitudinally in relation to theA die, pin means for pivotally mounting the carriage whereby said carriage may be swung around laterally to angular positions in relation to the die, crank actuated means for clamping the work holder in adjusted positions, and spring actuated spring means for securing said carriage in adjusted positions.

8. A forging tool having an elongated frame, a motor mounted on the frame, a horizontally disposed cylinder longitudinally positioned on the frame, a tool actuating piston positioned in one end of the cylinder, a Vmotor actuated piston in the opposite end of the cylinder and positioned in opposed relation to the tool actuating piston, means operatively connecting the motor to the said motor actuated piston, a tool actuated by the said tool actuating piston and slidably mounted for horizontal travel on the frame, a

work carrying base positioned on the frame, Y rollers mounting the base on the frame for longitudinal travel in alignment with the axis of the cylinder, a work holding carriage pivotally mounted on the base, guide members engaging the work and clamping the work on the carriage Aa motor mounted on the frame, a horizontally disposed cylinder longitudinally positioned on the frame, a tool actuating piston positioned in one end of the cylinder, a motor actuated piston in the opposite end of the cylinder and positioned in opposed relation to the tool actuating piston, means operatively connecting the motor to the said motor actuated piston, a tool actuated by the said tool actuating piston and slidably mounted for horizontal travel on the frame, a work carrying base positioned on the frame, means mounting the base on the frame for longitudinal travel in alignment with the axis of the cylinder, a Work holding carriage pivotally mounted on the base, means clamping work on the carriage with the work positioned to be acted upon by a tool actuated by the said tool actuating piston, a substantially semi-circular track with spaced openings therein extended from one side of the frame with the center thereof positioned on the pivotal mounting of the carriage and a spring pin carried by the carriage and positioned to coact with the spaced openings ofthe track to retain the carriage in adjusted positions.

10. A forging tool having an elongated frame, a motor mounted on the frame, a horizontally disposed cylinder longitudinally positioned on the frame, a tool actuating piston positioned in one end of the cylinder, a motor actuated piston in the opposite end of the cylinder and positioned in opposed relation to the tool actuating piston, means operatively connecting the motor to the said motor actuated piston, a tool actuated by the said tool actuating piston and slidably mounted for horizontal travel on the frame,

'a work carrying base positioned on the frame,

means mounting the base on the frame for longitudinal travel in alignment With the axis of the cylinder, a Work holding carriage pivotally mounted on the base, means clamping work on the carriage with the work positioned to be acted vupon by a tool actuated by the said tool actuating piston, a substantially semi-circular track with spaced openings therein extended from one side of the frame with the center thereof positioned on the pivotal mounting of the carriage, a spring pin carried by the carriage and positioned to coact with the spaced openings of the track to retain the carriage in adjusted position, a rack carried by the base, and a crank actuated pinion journaled in the frame and positioned to coact With the rack for adjusting the position of the base and carriage in relation to the tool.

ALBERT W. MITCHHART.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 68,888 Lamson Sept. 17, 1867 337,728 Arns Mar. 9, 1886 678,300 Krause July 9, 1901 834,441 Adams Oct. 30, 1906 915,362 Krause Mar. 16, 1909 1,072,358 Palmros Sept. 2, 1913 1,085,978 Gibson Feb. 3, 1914 1,389,501 Gorman et al Aug. 30, 1921 2,063,043 McKesson Dec. 8, 1936 2,091,408 Lewis Aug. 31, 1937 FOREIGN PATENTS Number Country Date 93,635 Switzerland Sept. 3, 1920 424,510 France May 16, 1911 

